Electric-current valve



Patented June 17, 193i) NITED STATES PATENT orrrcn:

ROBERT C. JACQUELET, OF NOBWOOD, OHIO ELECTRIC-CURRENT VALVE No Drawing.

while in service. The tendency of the recti fiers heretofore produced has been to de 15.crease in out-put over the course of the first several weeks of usage. Moreover, practically no two rectifiers behave in the same manner under exactly the same conditions.

Some lose their desirable properties more rapidly and.more completely than others.

Obviously a test lasting several weeks on each rectifier or on each plate thereof, which would be necessary to supply rectifiers for uses requiring any constancy would be a highly impractical and uncommercial proposition.

The pertinent characteristic of these copper oxide films is their diflerential resistance to currents oppositein direction. It is therefore requisite to stabilize two resistances; namely, the resistance to the useful current hereinafter called the useful resistance, and the resistance to the inverse current hereinafter called the inverse resistance.

The obj'ectof the present invention is to provide the process by which the resistance to the current phase to be suppressed can be developed and stabilized within a relatively short period of time, thereby permitting the segregation and elimination of those elements initially possessed of a predisposition to undesirable deterioration.

()ne important factor enters into the inverse resistance or its absence and that is the presence of ununiform spots or areas in the copper oxide film, which areas are often possessed of low, questionable or uncertain rectifying properties. These areas are often due to the presence of foreign matter in the 50 film but may also be due to other causes.

Application filed August 12, 1927. Serial No. 212,603.

When the rectifier is in service, the resistance often lessens gradually at and about these aforesaid areas, with the result that more inverse current leaks through and the output is diminished. This preinclination toward deterioration or decreasing resistance in minute and often isolated areas can be and is developed and detected by subjecting the rectifying element to a potential in the direction of the proposed inverse current of from 100 to 400 per cent greater than the potential to which the rectifying element was designed to be subjectedpreferably for a period of approximately an hour or less.

This process substantially develops the ultimate inverse resistance characteristics of the valve element, thereby permitting selection and discarding of elements in relation to the desired characteristics of the contemplated rectifier and its intended use.

Having described my invention, I claim: 1. The method of developing the ultimate inverse resistance of copper oxide current valves, which comprises, subjecting the elementsto electrical potential in the direction of the proposed inverse current, said potential from 100%400% in excess of that to which the elements are to be subjected in I service. a

2. The method of developing the ultimate inverse resistance of copper oxide current valves, which comprises, subjecting the elements to electrical potential in the direction of the proposed inverse current, said potential from 100%400% in excess of that to c which the elements are to be subjected in service- -for a period of approximately an hour.

In witness whereof, I hereunto subscribe n my name.

ROBERT C. JACQUELET. 

